Unmanned aerial vehicle inspection and attack integrated counter device with heat dissipation function
Patent Information
- Application Number
- CN202423284177.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-30
Smart Images
Figure CN223730159U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of unmanned aerial vehicle countermeasure equipment, in particular to an unmanned aerial vehicle searching and shooting integrated countermeasure device with heat dissipation function. BACKGROUND
[0002] As an important security device, the unmanned aerial vehicle searching and shooting integrated countermeasure device plays a key role in the modern security system. With the continuous progress of unmanned aerial vehicle technology, the application range of unmanned aerial vehicles is gradually expanding, covering military, civilian, air monitoring and other fields. These application scenarios put forward higher requirements for the performance of the unmanned aerial vehicle searching and shooting integrated countermeasure device, especially the stable operation ability in high temperature environment. Since a large number of electronic components are integrated inside the unmanned aerial vehicle searching and shooting integrated countermeasure device, a large amount of heat will be generated during the operation of these components. If heat dissipation is not timely, it will seriously affect the performance and service life of the device.
[0003] In order to solve this problem, the existing unmanned aerial vehicle searching and shooting integrated countermeasure device adopts a variety of heat dissipation methods. Common means include the use of heat sinks, heat dissipation fans and heat-conducting materials. For example, some devices increase the surface area of internal metal heat sinks to accelerate heat conduction; some devices use fans for forced heat dissipation, which brings in external cold air to take away internal heat; some devices use heat-conducting silicone grease and other materials to improve heat conduction efficiency. In addition, some devices have improved the shell design, such as adding heat dissipation holes or using materials with good thermal conductivity to improve the overall heat dissipation effect.
[0004] For the related technology in the above, although the above method alleviates the heat dissipation problem to a certain extent, there are still some deficiencies, especially for heat dissipation in high temperature environment. Single heat dissipation measure often fails to achieve ideal cooling effect. For example, relying solely on the natural heat dissipation speed of the heat sink is slow and cannot quickly reduce the internal temperature; while relying on the fan forced heat dissipation can effectively take away the heat, but in outdoor environment, the fan is easily affected by dust and moisture, resulting in shortened service life. Therefore, how to improve the heat dissipation effect of the unmanned aerial vehicle searching and shooting integrated countermeasure device and ensure its stable operation in high temperature environment is a key problem to be solved. Practical new type content
[0005] In order to overcome the above problems, the present application provides an unmanned aerial vehicle searching and shooting integrated countermeasure device with heat dissipation function.
[0006] The unmanned aerial vehicle searching and shooting integrated countermeasure device with heat dissipation function provided by the present application adopts the following technical scheme:
[0007] The utility model provides an unmanned aerial vehicle searches and hits integrated countermeasure device with heat dissipation function, including body, heat generating power amplifier module and heat dissipation device, the body includes main casing, the heat generating power amplifier module is fixed in the main casing, the heat dissipation device is connected to the main casing, the heat dissipation device is close to the heat generating power amplifier module, and the heat dissipation device is used to heat dissipation to the heat generating power amplifier module.
[0008] By adopting the above technical scheme, the unmanned aerial vehicle searches and hits integrated countermeasure device can effectively dissipate heat in a high-temperature environment, ensuring stable operation of the equipment. Specifically, the heat generating power amplifier module in the main casing dissipates heat through the heat dissipation device, which is in close proximity to the heat generating power amplifier module and can conduct and dissipate heat, improving the heat dissipation effect of the unmanned aerial vehicle searches and hits integrated countermeasure device, preventing internal electronic components from being damaged due to overheating, thereby prolonging the service life of the equipment and improving the reliability and safety of the equipment.
[0009] In a specific implementation, the main casing is provided with a through hole at the heat generating power amplifier module;
[0010] The heat dissipation device includes a heat dissipation assembly located in the through hole. The heat dissipation assembly includes an inner heat sink connected to the main casing and an outer heat sink located on the side of the inner heat sink away from the heat generating power amplifier module. The outer heat sink is arranged in parallel with the inner heat sink. The main casing is provided with a placement groove at the through hole for placing the outer heat sink. The outer heat sink is connected to the main casing, and the surface area of the outer heat sink is larger than that of the inner heat sink. A heat dissipation gap is left between the outer heat sink and the inner heat sink.
[0011] By adopting the above technical scheme, the inner heat sink is in contact with the heat generating power amplifier module, increasing the contact area and facilitating rapid heat conduction. The outer heat sink is arranged in parallel with the inner heat sink and has a larger surface area, increasing the surface area for natural cooling and improving the heat dissipation efficiency through radiation and convection. The heat dissipation gap avoids direct heat conduction and promotes natural cooling, improving the overall heat dissipation effect.
[0012] In a specific implementation, the surface of the inner heat sink away from the heat generating power amplifier module is integrally provided with a plurality of heat dissipation fins, which are distributed in a fin shape.
[0013] By adopting the above technical scheme, the surface area of the inner heat sink is significantly increased, improving the heat dissipation efficiency and enabling heat to be quickly conducted out of the heat generating power amplifier module and dissipated through the heat dissipation fins, thereby effectively reducing the temperature inside the equipment and improving the stable operation capability of the equipment in a high-temperature environment.
[0014] In a specific embodiment, the heat dissipation assembly further comprises two heat dissipation fans, both of which are located on the side of the inner heat dissipation fins close to the rear end of the main shell, and are connected to the main shell, with the air inlet of the heat dissipation fan facing the front end of the main shell and the air outlet facing the rear end of the main shell, forming a transverse airflow path, and the two heat dissipation fans are distributed along the length direction close to the side edge of the inner heat dissipation fins.
[0015] By adopting the above technical solution, specifically: the heat dissipation fan is located on the side of the inner heat dissipation fins close to the rear end of the main shell, so that the heat dissipation airflow can suck in cold air from the front end of the main shell, absorb the heat of the heat generating power amplifier module through the inner heat dissipation fins, and then discharge hot air from the rear end of the main shell, forming an effective transverse airflow path, accelerating the conduction and discharge of heat; the two heat dissipation fans are distributed along the length direction close to the side edge of the inner heat dissipation fins, ensuring uniform distribution of airflow on the entire inner heat dissipation fins, further improving the heat dissipation efficiency; this design not only effectively solves the heat dissipation problem of the equipment in high temperature environment, but also ensures the stable operation of the equipment, prolongs the service life of the equipment, and reduces the maintenance cost.
[0016] In a specific embodiment, the heat dissipation assembly further comprises two wind-blocking bubble cottons, which correspond one-to-one to the heat dissipation fans and are connected to the side of the heat dissipation fans away from the interior of the main shell.
[0017] By adopting the above technical solution, the wind-blocking bubble cotton corresponds one-to-one to the heat dissipation fan and is connected to the side of the heat dissipation fan away from the interior of the main shell, which can effectively block the backflow of hot air, ensure the smooth flow of heat dissipation airflow, and further improve the heat dissipation efficiency.
[0018] In a specific embodiment, the heat dissipation device further comprises a liquid cooling assembly, which comprises a liquid cooling plate, a heat dissipation pipeline, a radiator and a water pump, the liquid cooling plate is in close contact with the heat generating power amplifier module, the liquid cooling plate is connected to the main shell, one end of the heat dissipation pipeline is in communication with the liquid cooling plate, the other end is in communication with the radiator, and the water pump is fixed to the heat dissipation pipeline.
[0019] By adopting the above technical solution, the addition of the liquid cooling assembly significantly improves the overall heat dissipation efficiency of the equipment, specifically, the liquid cooling plate is in direct contact with the heat generating power amplifier module, absorbs a large amount of heat generated by it, and transmits the heat to the radiator through the water pump, and the radiator efficiently dissipates the heat to the air, this design not only significantly improves the heat dissipation performance of the equipment, but also optimizes the structural layout of the equipment, making it more suitable for various complex working environments, prolonging the service life of the equipment, and reducing the maintenance cost.
[0020] In a specific embodiment, a waterproof sealing pad is fixed at the connection between the heat-generating power amplifier module and the main shell inside the main shell.
[0021] By adopting the above technical solution, the waterproof sealing pad seals the connection between the heat-generating power amplifier module and the main shell, effectively preventing water from entering the interior of the main shell, protecting the internal electronic components from damage, and improving the waterproof performance and reliability of the equipment.
[0022] In a specific embodiment, the machine body further comprises a handle, which is integrally connected to the main shell.
[0023] By adopting the above technical solution, the integrated connection design of the handle improves the convenience and comfort of the user's operation, reduces the fatigue caused by long-time holding, and enhances the ergonomics of the equipment.
[0024] In summary, the present application includes at least one of the following beneficial technical effects:
[0025] 1. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function is designed, which can effectively dissipate heat in high temperature environment, ensuring stable operation of the equipment. Specifically, the heat-generating power amplifier module in the main shell is cooled by the heat dissipation device, which is in close proximity to the heat-generating power amplifier module and can conduct and dissipate heat, improving the heat dissipation effect of the unmanned aerial vehicle search and strike integrated countermeasure device, preventing internal electronic components from overheating and causing performance degradation or damage, thereby prolonging the service life of the equipment and improving the reliability and safety of the equipment.
[0026] 2. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function is designed, the internal heat dissipation fins are in close contact with the heat-generating power amplifier module, increasing the contact area and facilitating rapid heat conduction; the external heat dissipation fins are parallel to the internal heat dissipation fins and have a larger surface area, increasing the surface area for natural cooling and dissipating part of the absorbed heat through radiation and convection, improving the heat dissipation efficiency; the heat dissipation gap avoids direct heat conduction and promotes natural cooling, improving the overall heat dissipation effect.
[0027] 3. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function is designed, the addition of the liquid cooling assembly significantly improves the overall heat dissipation efficiency of the equipment. Specifically, the liquid cooling plate is in direct contact with the heat-generating power amplifier module, absorbing a large amount of heat generated by the module. The heat is transferred to the radiator by the water pump, and the radiator efficiently dissipates the heat to the air. This design not only significantly improves the heat dissipation performance of the equipment, but also optimizes the structural layout of the equipment, making it more suitable for various complex working environments, prolonging the service life of the equipment, and reducing maintenance costs. BRIEF DESCRIPTION OF DRAWINGS
[0028] Figure 1 is a schematic diagram of the overall structure in embodiment 1.
[0029] Figure 2 is a sectional view in embodiment 1.
[0030] Figure 3 is a partial schematic diagram of the heat dissipation assembly in embodiment 1.
[0031] Figure 4 is a schematic diagram of the overall structure in embodiment 2.
[0032] Figure 5 is a sectional view from a first perspective in embodiment 2.
[0033] Figure 6 is a sectional view from a second perspective in embodiment 2.
[0034] Reference signs: 1, body; 11, main shell; 111, through hole; 112, waterproof gasket; 113, placement groove; 12, handle; 2, heat generating power amplifier module; 3, heat dissipation device; 31, heat dissipation assembly; 311, inner heat dissipation fin; 3111, heat dissipation fin; 312, outer heat dissipation fin; 313, heat dissipation fan; 314, wind-blocking bubble cotton; 32, liquid cooling assembly; 321, liquid cooling plate; 322, heat dissipation pipeline; 323, radiator; 324, water pump. DETAILED DESCRIPTION
[0035] The following will be described in detail in combination with the accompanying Figures 1-6 The present application is further described in detail.
[0036] The embodiment of the present application discloses a UAV search and strike integrated countermeasure device with heat dissipation function.
[0037] Embodiment 1
[0038] Referring to Figure 1 and Figure 2 A UAV search and strike integrated countermeasure device with heat dissipation function includes a body 1, a heat generating power amplifier module 2 and a heat dissipation device 3, and the heat generating power amplifier module 2 and the heat dissipation device 3 are arranged in the body 1.
[0039] Referring to Figure 1 The body 1 includes a main shell 11 and a handle 12, the main shell 11 is used for placing a circuit module and a power supply module, the main shell 11 is made of high-strength and light-weight aluminum alloy material, not only has good mechanical strength, but also can effectively reduce the weight of the equipment, and is convenient for single soldier to carry, the handle 12 is located at the bottom of the main shell 11, and the handle 12 is integrally connected to the main shell 11, so as to facilitate personnel to carry.
[0040] Referring to Figure 1 and Figure 2The heat generating power amplifier module 2 is located in the main shell 11, and the heat generating power amplifier module 2 is fixedly connected with the main shell 11 through screws. The main shell 11 is provided with a through hole 111 at the heat generating power amplifier module 2. The heat generating power amplifier module 2 is located at the through hole 111. A waterproof sealing gasket 112 is arranged between the heat generating power amplifier module 2 and the main shell 11 inside the main shell 11. The waterproof sealing gasket 112 is fixedly bonded to the main shell 11. The waterproof sealing gasket 112 seals the connection between the heat generating power amplifier module 2 and the main shell 11. The waterproof sealing gasket 112 is made of silicone rubber material, has excellent softness and elasticity, can maintain good sealing performance at different temperatures, prevents water from entering the inside of the main shell 11, and protects the internal electronic components from damage.
[0041] With reference to Figure 2 and Figure 3 The heat dissipation device 3 comprises a heat dissipation assembly 31. The heat dissipation assembly 31 is located in the through hole 111. The heat dissipation assembly 31 comprises an inner heat dissipation fin 311, an outer heat dissipation fin 312, two heat dissipation fans 313 and two wind-blocking bubble cottons 314. The inner heat dissipation fin 311 is close to the heat generating power amplifier module 2. The inner heat dissipation fin 311 is fixedly connected to the main shell 11 through screws. The inner heat dissipation fin 311 is attached to the heat generating power amplifier module 2. The inner heat dissipation fin 311 is designed to be flat, which increases the contact area with the heat generating power amplifier module 2, is conducive to rapid heat conduction, and is made of aluminum alloy material with high thermal conductivity, has good heat transfer performance, and has a thickness of about 2 mm, a length of 100 mm and a width of 50 mm, which can effectively cover the main heat generating area of the heat generating power amplifier module 2.
[0042] With reference to Figure 2 The surface of the inner heat dissipation fin 311 is provided with a plurality of heat dissipation fins 3111. The heat dissipation fins 3111 are integrally arranged on the inner heat dissipation fin 311. The plurality of heat dissipation fins 3111 are distributed in a fin shape, which increases the surface area of the inner heat dissipation fin 311 and improves the heat dissipation efficiency. The height of the heat dissipation fin 3111 is 5 mm, and the interval is 10 mm. The heat dissipation fins 3111 are uniformly distributed on the surface of the inner heat dissipation fin 311, forming a dense heat dissipation network.
[0043] With reference to Figure 2The outer heat dissipation fin 312 is located on the side of the inner heat dissipation fin 311 away from the heat generating power amplifier module 2, and the outer heat dissipation fin 312 is arranged in parallel with the inner heat dissipation fin 311. The main shell 11 is provided with a placing groove 113 for placing the outer heat dissipation fin 312 at the through hole 111. The outer heat dissipation fin 312 is fixedly connected to the main shell 11 by screws. The surface area of the outer heat dissipation fin 312 is larger than that of the inner heat dissipation fin 311, thereby increasing the surface area for natural cooling. The outer heat dissipation fin 312 is made of a lightweight and high-strength composite material, which not only reduces the overall weight but also does not affect the heat dissipation effect. The outer heat dissipation fin 312 dissipates part of the absorbed heat through radiation and convection. The outer heat dissipation fin 312 and the inner heat dissipation fin 311 are spaced apart to avoid direct heat conduction and increase the surface area for natural cooling. The thickness of the outer heat dissipation fin 312 is about 3 mm, and the length and width are 120 mm and 60 mm, respectively, which can effectively absorb and dissipate heat.
[0044] With reference to Figure 2 and Figure 3 The two heat dissipation fans 313 are located on the side of the inner heat dissipation fin 311 close to the rear end of the main shell 11. The air inlet of the heat dissipation fan 313 is located at the front end of the main shell 11, and the air outlet is located at the rear end, forming a horizontal airflow path, which is conducive to the circulation of the heat dissipation airflow. The two heat dissipation fans 313 are distributed along the length direction of the side close to the inner heat dissipation fin 311. The mounting bracket of the heat dissipation fan 313 is fixedly connected to the main shell 11 by screws to ensure the stability and reliability of the fan. The wire hole of the heat dissipation fan 313 is treated with glue to prevent water, further improving the waterproof performance of the equipment. The heat dissipation fan 313 selects a high-efficiency and low-noise DC waterproof fan with moderate power to meet the long-term continuous operation requirement.
[0045] With reference to Figure 3 The wind-blocking bubble cotton 314 corresponds to the heat dissipation fan 313 one by one. The wind-blocking bubble cotton 314 is located behind the heat dissipation fan 313 to block the backflow of heat and further improve the heat dissipation efficiency. The wind-blocking bubble cotton 314 is fixedly connected to the heat dissipation fan 313 by screws. The wind-blocking bubble cotton 314 is made of a professional dustproof and heat-insulating gap material, which has excellent air permeability and weather resistance and can maintain good performance in harsh environments. The thickness of the wind-blocking bubble cotton 314 is about 5 mm, and the size is matched with the heat dissipation fan 313 to ensure effective blocking of the backflow of heat.
[0046] The implementation principle of embodiment 1 is that when the unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function starts to work, the heat dissipation fan 313 starts to work, generates strong suction, sucks in cold air from the front end of the main shell 11, and after the heat dissipation fins 311 absorb the heat from the heat generating power amplifier module 2, the heat dissipation fins 311 become hot air, which is prevented from continuing to flow forward by the wind-blocking bubble cotton 314 and is discharged outside the main shell 11 along the preset path. At this time, the outer heat dissipation fins 312, by virtue of their good heat dissipation characteristics, dissipate part of the absorbed heat through radiation and convection, thereby realizing the double heat dissipation mechanism of the inside and outside. During the whole process, the waterproof sealing gasket 112 effectively isolates the external moisture, protects the internal circuit from damage, significantly improves the overall heat dissipation efficiency of the device, optimizes the portability and ergonomics of the device, reduces the fatigue caused by long-time holding, enhances the environmental adaptability and durability of the device, prolongs the service life, and reduces the maintenance cost.
[0047] Embodiment 2
[0048] With reference to Figure 4 and Figure 5 , the difference between this embodiment and embodiment 1 is that the heat dissipation device 3 further comprises a liquid cooling assembly 32, which is located in the main shell 11,
[0049] With reference to Figure 5 and Figure 6 , the liquid cooling assembly 32 comprises a liquid cooling plate 321, a heat dissipation pipeline 322, a radiator 323 and a water pump 324. The liquid cooling plate 321 is close to the heat generating power amplifier module 2 and is in close contact with the heat generating power amplifier module 2 to absorb the heat generated thereby. The liquid cooling plate 321 is fixedly connected to the main shell 11 by screws. One end of the heat dissipation pipeline 322 is in communication with the liquid cooling plate 321, and the other end is in communication with the radiator 323. The heat dissipation pipeline 322 is fixedly connected to the radiator 323 by screws. The water pump 324 is fixedly connected to the heat dissipation pipeline 322 by a flange. The water pump 324 sends the cooling liquid from the radiator 323 to the liquid cooling plate 321, transfers the heat to the cooling liquid through the liquid cooling plate 321, and then the cooling liquid flows back to the radiator 323, which dissipates the heat to the air. The radiator 323 adopts large-area aluminum heat dissipation fins, which have good heat dissipation performance. The heat dissipation pipeline 322 adopts high-temperature-resistant plastic material to ensure the smooth circulation of the cooling liquid.
[0050] The implementation principle of embodiment 2 is that the addition of the liquid cooling assembly 32 realizes the high-efficiency liquid cooling function. The liquid cooling plate 321 directly contacts the heat generating power amplifier module 2 to absorb the heat generated thereby, and the water pump 324 transfers the heat to the radiator 323, which dissipates the heat to the air, thereby realizing the high-efficiency heat dissipation effect. This design not only significantly improves the overall heat dissipation efficiency of the device, but also optimizes the structural layout of the device, which is suitable for various complex working environments.
[0051] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, and thus: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.
Claims
1. A drone detection and countermeasure device with heat dissipation function, characterized in that: The utility model provides a heat dissipation device of power amplifier module, including body (1), heat generating power amplifier module (2) and heat dissipation device (3), the body (1) includes main casing (11), the heat generating power amplifier module (2) is fixed in the main casing (11), the heat dissipation device (3) is connected to the main casing (11), the heat dissipation device (3) is close to the heat generating power amplifier module (2), the heat dissipation device (3) is used to the heat dissipation of heat generating power amplifier module (2).
2. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function according to claim 1, characterized in that: The main casing (11) is provided with a through hole (111) at the heat generating power amplifier module (2); The heat dissipation device (3) includes a heat dissipation assembly (31), which is located in the through hole (111). The heat dissipation assembly (31) includes an inner heat dissipation fin (311) and an outer heat dissipation fin (312). The inner heat dissipation fin (311) is connected to the main casing (11) and is in contact with the heat generating power amplifier module (2). The outer heat dissipation fin (312) is located on the side of the inner heat dissipation fin (311) away from the heat generating power amplifier module (2). The outer heat dissipation fin (312) is arranged in parallel with the inner heat dissipation fin (311). The main casing (11) is provided with a placement groove (113) at the through hole (111) for placing the outer heat dissipation fin (312). The outer heat dissipation fin (312) is connected to the main casing (11). The surface area of the outer heat dissipation fin (312) is larger than that of the inner heat dissipation fin (311). There is a heat dissipation gap between the outer heat dissipation fin (312) and the inner heat dissipation fin (311).
3. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function according to claim 2, characterized in that: A plurality of heat dissipation fins (3111) are integrally arranged on the surface of the inner heat dissipation fin (311) away from the heat generating power amplifier module (2). The plurality of heat dissipation fins (3111) are distributed in a fin shape.
4. The unmanned aerial vehicle search and attack integrated countermeasure device with heat dissipation function according to claim 2, characterized in that: The heat dissipation assembly (31) further includes two heat dissipation fans (313). The two heat dissipation fans (313) are located on the side of the inner heat dissipation fin (311) close to the rear end of the main casing (11). The heat dissipation fans (313) are connected to the main casing (11). The air inlet of the heat dissipation fans (313) faces the front end of the main casing (11), and the air outlet faces the rear end of the main casing (11), forming a horizontal airflow path. The two heat dissipation fans (313) are distributed along the length direction of the side of the inner heat dissipation fin (311) close to the main casing (11).
5. The unmanned aerial vehicle search and strike integrated countermeasure device with heat dissipation function according to claim 4, characterized in that: The heat dissipation assembly (31) further includes two wind-blocking bubble cottons (314). The wind-blocking bubble cottons (314) correspond to the heat dissipation fans (313) one by one. The wind-blocking bubble cottons (314) are connected to the side of the heat dissipation fans (313) away from the interior of the main casing (11).
6. The unmanned aerial vehicle search and attack integrated countermeasure device with heat dissipation function according to claim 1, characterized in that: The heat dissipation device (3) further comprises a liquid cooling assembly (32), the liquid cooling assembly (32) comprises a liquid cooling plate (321), a heat dissipation pipeline (322), a heat sink (323) and a water pump (324), the liquid cooling plate (321) is in close contact with the heat generating power amplifier module (2), the liquid cooling plate (321) is connected to the main shell (11), one end of the heat dissipation pipeline (322) is communicated with the liquid cooling plate (321), the other end is communicated with the heat sink (323), and the water pump (324) is fixed on the heat dissipation pipeline (322).
7. The unmanned aerial vehicle search and attack integrated countermeasure device with heat dissipation function according to claim 1, characterized in that: The main shell (11) is internally fixed with a waterproof sealing gasket (112) at the connecting part between the heat generating power amplifier module (2) and the main shell (11), and the waterproof sealing gasket (112) seals the connecting part between the heat generating power amplifier module (2) and the main shell (11).
8. The unmanned aerial vehicle search and attack integrated countermeasure device with heat dissipation function according to claim 1, characterized in that: The machine body (1) further comprises a handle (12), and the handle (12) is integrally connected to the main shell (11).